Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

What are the vitamins which make up the b complex, Q. What are the vitamins...

Q. What are the vitamins which make up the B complex? Which problems does the lack of these vitamins cause? Vitamins of the B complex are: vitamin B1 or thiamin, riboflavin, or

Define briefly about the seed proteins, Define briefly about the Seed Prote...

Define briefly about the Seed Proteins? Although a large number of plants produce seeds having protein contents in excess of 15%, only a few are utilized for food, eg. soybean,

Types of advanced plaques, The presence of advanced plaques of types IV and...

The presence of advanced plaques of types IV and Va allows clinical symptoms to develop. Atherosclerosis is a biphasic disease; in the first stage, advanced plaques are generated b

Cell, what is cell and what are the components of cell

what is cell and what are the components of cell

Malignant catarrhal fever (mcf), M a l i g nant catarrhal fever (MCF) ...

M a l i g nant catarrhal fever (MCF) Malignant catarrhal fever is invariably fatal generalized lymphoproliferative disease of cattle and sometimes of wild ruminants. It is

Why do leaves change color, Why do leaves change color? Leave is the fo...

Why do leaves change color? Leave is the food factories of plants. During the spring and summer, leaves are actively making food and they are filled with chlorophyll, which giv

Causes of cancer, Causes of Cancer We know earlier that a malignant tu...

Causes of Cancer We know earlier that a malignant tumor is a large aggregation of cancer cells, all of them descended from a single founder cell that was once a normal cell wi

What are the cytoplasmic inclusions, Q. What are the cytoplasmic inclusions...

Q. What are the cytoplasmic inclusions? Cytoplasmic inclusions are cytoplasmic molecular aggregates, such as organic polymers, pigments and crystals. They are not considered ce

Risk of embolization, Systemic embolization occurs in 22 per cent to 50 per...

Systemic embolization occurs in 22 per cent to 50 per cent of cases of IE. Emboli often involve major arterial beds, including lungs, coronary arteries, spleen, bowel, and extremit

Metalimnion - summer stratification, Metalimnion - Summer Stratification ...

Metalimnion - Summer Stratification This zone lies below the epilimnion and above the hypolimnion and thus forms the intermediate layer which is non-circulating. The metalimni

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd